Mechanical calculator.



J. B. SKEEN.

MECHANICAL CALCULATOR.

APPLICATION FILED 0CT.25.1915.

Patented Dec 17,1918.

2 SHEETS-SHEET I.

JESSE 13. SKEEN, OF LOS ANGELES, CALIFORNIA.

MECHANICAL CALCULATOR.

Specification of Letters Patent.

Patented Dec. 17, 1918.

Application filed October 25, 1915. Serial N 0. 57,703.

To all whom it may concern Be it known that I, Jnssn B. SHEEN, a citizenof the United States, residing at the city of Los Angeles, in the countyof Los Angelcs and State of California, have invented new and usefulImprovements in Mechanical Calculators of which the follow ing is aspecification.

My invention relates to the mechanical manipulation of tables forfacilitating and expediting arithmetical calculations such as computingcontents of triangular solids,

computing wages, interest, trigonometrical problems and other likecalculations.

I have illustrated my device in the accompanying drawings as applied tocomputing the contents of triangular solids and WM describe it as soapplied.

In the drawings:

Figure 1 is an end elevation, partly broken away, of my calculator.

Fig. 2 is a top plan of Fig. 1 with parts in section.

Fig. 3 is an enlarged sectional detail on the line 3-3 of Fig. 1.

Fig. 4: is a bottom plan of a portion of Fig.

Fig. 5 is a top plan of Fig. 3, with a part broken away.

Fig. 6 is a-fragment of the table used in computing the contents oftriangular solids.

While different tables may be mounted on the cylinder of this device,this description will be confined to the use of an earth work table, afragment of which is shown in Fig. 6, consisting of calculated volumesof triangular sections fifty feet long, having bases varying fromone-tenth of a foot to onehundred feet and any given altitude, it beingunderstood however, that the principle underlying the use of the earthwork table applies to the manipulation of other tables. The differenttables would be arranged on the cylinder in the form best suited toperform their functions, with a possible variation in the number of keyson the index dial.

In the drawings 10 is a base plate on which are mounted standard 11 andend plate 12. A shaft 13 is revolubly mounted in said standard andplate. A table cylin der 14, preferably hollow, is secured upon andcarried by said shaft. On the periphery of the cylinder is mounted table15 which is used in calculating the contents of triangu lar solids as inearth work calculations in railroad work. Ciroumferentially the table isarranged for calculations up to twenty feet, which may be used as eitherbase or altitude. In the illustration it is the base, and each foot issubdivided into tenths. Each tenth of foot has a line of longitudi nalcomputations correctly worked out representing either base or altitude.In this illustration it represents altitude. Each longitudinal line ofcomputations is divided into groups of nine members so that in thepresent illustration we have a table composed of five groups and in eachgroup there are nine circumferential columns of two hundred numbers.

The first group runs from 0.1 to 20 feet. The second group runs from20.1 feet to 4-0 feet. The third group runs from 40.1 feet to feet. Thefourth group runs from 60.1

to 80 feet. The fifth group runs from 80.1

to 100 feet. Additional groups can be added by lengthening the cylinder.

The first circumferential column is an indeX column. The circumferentialcolumn numbers of the second and subsequent columns are found bymultiplying the several numbers of the first or index column by thequotient of twenty-five divided by twentyseven, but as this quotient isan interminable decimal I only use the first two figures there of andwhen the decimals to the right of the hundredths place exceed five Idrop the decimals to the right of the hundredth place and add one to thehundredths figure.

On shaft 13 is secured a bevel gear 16 which meshes with a bevel gear 17on shaft 18. On the other end of shaft 18 is a bevel gear 19 whichmeshes with bevel gear 20 on shaft 21. Shaft 18 is mounted in bearings22 and 23 secured to end plate 12. Shaft 21 is mounted in bearings 24:also secured to end plate 12. A portion of end plate 12 is bent over asbest shown in Figs. 1 and 3 and shaft 21 also passes through this part.A detent plate 25 best shown in Figs. 3 and 4 is secured to the bentover portion of plate 12 by rivet 26.

Shaft 21 has a head 21- which passes through the detent plate therebykeeping the plate from rotating on rivet 26. In the outer end of thedetent plate are ten notches numbered from 0 to 9 and indicated by thenumeral 27. These notches are engaged as desired by a detent 28 which isheld by spring 29 in engagement with the detent plate at any desirednotch. Detent 28 is carried by the handle 30 of what may be ranged 011 acircle and are held out of engagement with the tenth plate by springs,one of which 35, is shown in Fig. 3. Marked on the face of the indexdial are the respective numbers of these pins which numbering runs fromone to twenty as best shown in Fig. 2. The numbers could be placed onthe heads of the pins. The index dial is rigidly attached to the head ofshaft- 21 by rivets 36 so that said shaft will rotate when said dial isrotated. Cylinder 14 and gears 16 and 17 are inclosed in a casing 37which is fastened to the base plate. This casing has a longitudinalsight aperture 38 which is covered by a transparent sight strip 39,preferably of glass, which has a sight line 40 running longitudinallythereof and group lines running transversely thereof. Indexes for thedifferent groups are placed on the glass just above the sight line.

In the use of my device suppose I wish to know the cubic contents ofearth work in a triangular section with a base of nineteen andnine-tenths feet and one foot altitude. I first turn the tenth plate tothe position that the detent engages the notch marked 9. I then turn theindex dial by means of the stop pin marked 19 and when said stop pincomes over the detent plate I apply a pressure on the top of the pin sothat when the pin registers with the stop hole 33 the pin will enter itand stop the further movement of the index dial.

The movement of the index dial has caused through the connected shaftsand gears the revolution of cylinder 14: to bring the longitudinal lineof figures which give the desired answer at rest below the sight line onthe sight glass. I then look at the first number of the group indexmarked 0.1 to 20 and read opposite 19.9 of the index column 18.3t3 cubicyards as my answer. If the base had been 99.9 feet instead of 19.9 feetand the altitude 9 feet instead of one foot'I would have looked in thelast column of the group 80.1 to 100 opposite 19.9 of the index columnand would have read 832.50 cubic yards as my answer.

By using other tables with suitable indexes on cylinder 14 and suitablyspaced stop pins on the index dial my mechanism can be used for a largenumber of arithmetical calculations, the principle of operation being arevolving cylinder carrying the table; an index dial workably connectedto the cylinder so that each revolution of the index dial will cause onerevolution of the table cylinder; and suitable stop mechanism by whichthe index dial may be stopped at any point of its revolution at a givenpoint and when so stopped a specific portion of the table cylinder willappear at a given point. The point at which the index dial stops willcause the stoppage of the table cylinder at the desired point to furnishthe information wanted.

Having described my invention what I claim is:

A mechanical calculator comprising a base plate; a movable chart,bearing tables revolubly mounted on said base plate; a tenth platehaving a stop hole therein adjustably mounted on said base plate; anindex dial revolubly mounted on said base plate; an

operative connection between said cylinder and dial; and stop pinsmounted on said dial,

7 said pins being adapted when pressure is applied thereto to enter thestop hole and prevent further rotation of said dial whereby the tablecylinder is stopped in a predetermined position.

In-witness that I claim the foregoing I have hereunto subscribed myname.

JEssE B. SKEEN.

Copies 01' this patent may be obtained for five cents each, byaddressing the Commissioner of Patents,

Washington, no."

